// Copyright 2014 The Flutter Authors. All rights reserved.
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.

import 'package:flutter/material.dart';

/// Flutter code sample for [RawScrollbar].

void main() => runApp(const RawScrollbarExampleApp());

class RawScrollbarExampleApp extends StatelessWidget {
  const RawScrollbarExampleApp({super.key});

  @override
  Widget build(BuildContext context) {
    return MaterialApp(
      home: Scaffold(
        appBar: AppBar(title: const Text('RawScrollbar Sample')),
        body: const Center(
          child: RawScrollbarExample(),
        ),
      ),
    );
  }
}

class RawScrollbarExample extends StatefulWidget {
  const RawScrollbarExample({super.key});

  @override
  State<RawScrollbarExample> createState() => _RawScrollbarExampleState();
}

class _RawScrollbarExampleState extends State<RawScrollbarExample> {
  final ScrollController _controller = ScrollController();

  @override
  void dispose() {
    _controller.dispose();
    super.dispose();
  }

  @override
  Widget build(BuildContext context) {
    return LayoutBuilder(builder: (BuildContext context, BoxConstraints constraints) {
      return Row(
        children: <Widget>[
          SizedBox(
            width: constraints.maxWidth / 2,
            // When using the PrimaryScrollController and a Scrollbar
            // together, only one ScrollPosition can be attached to the
            // PrimaryScrollController at a time. Providing a
            // unique scroll controller to this scroll view prevents it
            // from attaching to the PrimaryScrollController.
            child: Scrollbar(
              thumbVisibility: true,
              controller: _controller,
              child: ListView.builder(
                controller: _controller,
                itemCount: 100,
                itemBuilder: (BuildContext context, int index) {
                  return Padding(
                    padding: const EdgeInsets.all(8.0),
                    child: Text('Scrollable 1 : Index $index'),
                  );
                },
              ),
            ),
          ),
          SizedBox(
            width: constraints.maxWidth / 2,
            // This vertical scroll view has primary set to true, so it is
            // using the PrimaryScrollController. On mobile platforms, the
            // PrimaryScrollController automatically attaches to vertical
            // ScrollViews, unlike on Desktop platforms, where the primary
            // parameter is required.
            child: Scrollbar(
              thumbVisibility: true,
              child: ListView.builder(
                primary: true,
                itemCount: 100,
                itemBuilder: (BuildContext context, int index) {
                  return Container(
                    height: 50,
                    color: index.isEven ? Colors.amberAccent : Colors.blueAccent,
                    child: Padding(
                      padding: const EdgeInsets.all(8.0),
                      child: Text('Scrollable 2 : Index $index'),
                    ),
                  );
                },
              ),
            ),
          ),
        ],
      );
    });
  }
}
